TripleDESCryptoServiceProvider Class

 

Defines a wrapper object to access the cryptographic service provider (CSP) version of the TripleDES algorithm. This class cannot be inherited.

Namespace:   System.Security.Cryptography
Assembly:  mscorlib (in mscorlib.dll)

System::Object
  System.Security.Cryptography::SymmetricAlgorithm
    System.Security.Cryptography::TripleDES
      System.Security.Cryptography::TripleDESCryptoServiceProvider

[ComVisibleAttribute(true)]
public ref class TripleDESCryptoServiceProvider sealed : TripleDES

NameDescription
System_CAPS_pubmethodTripleDESCryptoServiceProvider()

Initializes a new instance of the TripleDESCryptoServiceProvider class.

NameDescription
System_CAPS_pubpropertyBlockSize

Gets or sets the block size, in bits, of the cryptographic operation.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyFeedbackSize

Gets or sets the feedback size, in bits, of the cryptographic operation.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyIV

Gets or sets the initialization vector (IV) for the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyKey

Gets or sets the secret key for the TripleDES algorithm.(Inherited from TripleDES.)

System_CAPS_pubpropertyKeySize

Gets or sets the size, in bits, of the secret key used by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyLegalBlockSizes

Gets the block sizes, in bits, that are supported by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyLegalKeySizes

Gets the key sizes, in bits, that are supported by the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyMode

Gets or sets the mode for operation of the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubpropertyPadding

Gets or sets the padding mode used in the symmetric algorithm.(Inherited from SymmetricAlgorithm.)

NameDescription
System_CAPS_pubmethodClear()

Releases all resources used by the SymmetricAlgorithm class.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubmethodCreateDecryptor()

Creates a symmetric decryptor object with the current Key property and initialization vector (IV).(Inherited from SymmetricAlgorithm.)

System_CAPS_pubmethodCreateDecryptor(array<Byte>^, array<Byte>^)

Creates a symmetric TripleDES decryptor object with the specified key (Key) and initialization vector (IV).(Overrides SymmetricAlgorithm::CreateDecryptor(array<Byte>^, array<Byte>^).)

System_CAPS_pubmethodCreateEncryptor()

Creates a symmetric encryptor object with the current Key property and initialization vector (IV).(Inherited from SymmetricAlgorithm.)

System_CAPS_pubmethodCreateEncryptor(array<Byte>^, array<Byte>^)

Creates a symmetric TripleDES encryptor object with the specified key (Key) and initialization vector (IV).(Overrides SymmetricAlgorithm::CreateEncryptor(array<Byte>^, array<Byte>^).)

System_CAPS_pubmethodDispose()

Releases all resources used by the current instance of the SymmetricAlgorithm class.(Inherited from SymmetricAlgorithm.)

System_CAPS_pubmethodEquals(Object^)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGenerateIV()

Generates a random initialization vector (IV) to use for the algorithm.(Overrides SymmetricAlgorithm::GenerateIV().)

System_CAPS_pubmethodGenerateKey()

Generates a random Key to be used for the algorithm.(Overrides SymmetricAlgorithm::GenerateKey().)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubmethodValidKeySize(Int32)

Determines whether the specified key size is valid for the current algorithm.(Inherited from SymmetricAlgorithm.)

This algorithm supports key lengths from 128 bits to 192 bits in increments of 64 bits.

System_CAPS_noteNote

A newer symmetric encryption algorithm, Advanced Encryption Standard (AES), is available. Consider using the AesCryptoServiceProvider class instead of the TripleDESCryptoServiceProvider class. Use TripleDESCryptoServiceProvider only for compatibility with legacy applications and data.

The following code example creates a TripleDESCryptoServiceProvider object and uses it to encrypt and decrypt data in a file.

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
void EncryptTextToFile( String^ Data, String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create or open the specified file.
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );

      // Create a CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew TripleDESCryptoServiceProvider)->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );

      // Create a StreamWriter using the CryptoStream.
      StreamWriter^ sWriter = gcnew StreamWriter( cStream );

      // Write the data to the stream 
      // to encrypt it.
      sWriter->WriteLine( Data );

      // Close the streams and
      // close the file.
      sWriter->Close();
      cStream->Close();
      fStream->Close();
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
   }
   catch ( UnauthorizedAccessException^ e ) 
   {
      Console::WriteLine( "A file access error occurred: {0}", e->Message );
   }

}

String^ DecryptTextFromFile( String^ FileName, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create or open the specified file. 
      FileStream^ fStream = File::Open( FileName, FileMode::OpenOrCreate );

      // Create a CryptoStream using the FileStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( fStream,(gcnew TripleDESCryptoServiceProvider)->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );

      // Create a StreamReader using the CryptoStream.
      StreamReader^ sReader = gcnew StreamReader( cStream );

      // Read the data from the stream 
      // to decrypt it.
      String^ val = sReader->ReadLine();

      // Close the streams and
      // close the file.
      sReader->Close();
      cStream->Close();
      fStream->Close();

      // Return the string. 
      return val;
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }
   catch ( UnauthorizedAccessException^ e ) 
   {
      Console::WriteLine( "A file access error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {

      // Create a new TripleDESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      TripleDESCryptoServiceProvider^ tDESalg = gcnew TripleDESCryptoServiceProvider;

      // Create a string to encrypt.
      String^ sData = "Here is some data to encrypt.";
      String^ FileName = "CText.txt";

      // Encrypt text to a file using the file name, key, and IV.
      EncryptTextToFile( sData, FileName, tDESalg->Key, tDESalg->IV );

      // Decrypt the text from a file using the file name, key, and IV.
      String^ Final = DecryptTextFromFile( FileName, tDESalg->Key, tDESalg->IV );

      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

The following code example creates a TripleDESCryptoServiceProvider object and uses it to encrypt and decrypt data in memory.

using namespace System;
using namespace System::Security::Cryptography;
using namespace System::Text;
using namespace System::IO;
array<Byte>^ EncryptTextToMemory( String^ Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create a MemoryStream.
      MemoryStream^ mStream = gcnew MemoryStream;

      // Create a CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ cStream = gcnew CryptoStream( mStream,(gcnew TripleDESCryptoServiceProvider)->CreateEncryptor( Key, IV ),CryptoStreamMode::Write );

      // Convert the passed string to a byte array.
      array<Byte>^toEncrypt = (gcnew ASCIIEncoding)->GetBytes( Data );

      // Write the byte array to the crypto stream and flush it.
      cStream->Write( toEncrypt, 0, toEncrypt->Length );
      cStream->FlushFinalBlock();

      // Get an array of bytes from the 
      // MemoryStream that holds the 
      // encrypted data.
      array<Byte>^ret = mStream->ToArray();

      // Close the streams.
      cStream->Close();
      mStream->Close();

      // Return the encrypted buffer.
      return ret;
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

String^ DecryptTextFromMemory( array<Byte>^Data, array<Byte>^Key, array<Byte>^IV )
{
   try
   {

      // Create a new MemoryStream using the passed 
      // array of encrypted data.
      MemoryStream^ msDecrypt = gcnew MemoryStream( Data );

      // Create a CryptoStream using the MemoryStream 
      // and the passed key and initialization vector (IV).
      CryptoStream^ csDecrypt = gcnew CryptoStream( msDecrypt,(gcnew TripleDESCryptoServiceProvider)->CreateDecryptor( Key, IV ),CryptoStreamMode::Read );

      // Create buffer to hold the decrypted data.
      array<Byte>^fromEncrypt = gcnew array<Byte>(Data->Length);

      // Read the decrypted data out of the crypto stream
      // and place it into the temporary buffer.
      csDecrypt->Read( fromEncrypt, 0, fromEncrypt->Length );

      //Convert the buffer into a string and return it.
      return (gcnew ASCIIEncoding)->GetString( fromEncrypt );
   }
   catch ( CryptographicException^ e ) 
   {
      Console::WriteLine( "A Cryptographic error occurred: {0}", e->Message );
      return nullptr;
   }

}

int main()
{
   try
   {

      // Create a new TripleDESCryptoServiceProvider object
      // to generate a key and initialization vector (IV).
      TripleDESCryptoServiceProvider^ tDESalg = gcnew TripleDESCryptoServiceProvider;

      // Create a string to encrypt.
      String^ sData = "Here is some data to encrypt.";

      // Encrypt the string to an in-memory buffer.
      array<Byte>^Data = EncryptTextToMemory( sData, tDESalg->Key, tDESalg->IV );

      // Decrypt the buffer back to a string.
      String^ Final = DecryptTextFromMemory( Data, tDESalg->Key, tDESalg->IV );

      // Display the decrypted string to the console.
      Console::WriteLine( Final );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( e->Message );
   }

}

.NET Framework
Available since 1.1

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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